Overview
The_Amazing_World_of_Gumball is a English written tag for The Amazing World of Gumball. Due to pixiv tags not having spaces it can be hard to write something in English. Some users have resorted to using a underscore as spaces.
Since TheAmazingWorldofGumball is not case-sensitive and is not separated by underscores, partial match search is recommended in pixiv search.
For more details refer to the article The Amazing World of Gumball.